Light sources are frequently applied in several types of atmosphere and ambience lighting applications for creating mood in e.g. a living room. More and more, these light sources comprise a plurality of light emitting diodes (LEDs), which can emit different colors. Mixing of colors and collimation of the light beams are particularly relevant issues for these lighting applications.
U.S. Pat. No. 6,334,700 discloses a direct view lighting system with a constructive occlusion providing a tailored radiation intensity distribution adapted to meet the requirements of certain special applications. Some radiant energy from the system source reflects and diffuses within the volume between a mask and a cavity. The mask constructively occludes the aperture of the cavity. The reflected energy emerging from between the mask and cavity provides a desired illumination for regions not covered by the direct illumination.
A problem of the prior art lamp assembly is that the mask of the assembly obstructs a considerable portion of the light having diffusely reflected once from the surface of the cavity. Consequently, only limited regions can be illuminated by the light beams reflected from the surface of the cavity.